Adjusting means for telescopes



A. LANGSNER ADJUSTING MEANS FOR TELESCOHES Original Filed Feb. 4, 1938INVENTOR. fldaa/zlagwzer AORNEY6,

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Patented Apr. 15, 1941 ADJUSTING MEANS FOR TELESCOPES Adolph Langsner,Chicago, Ill., assignor to Eugene Dietzgen 00., Chicago, Ill., acorporation of Delaware Original application February 4, 1938, SerialNo. 188,595. Divided and this application November 17, 1938, Serial No.241,011

5 Claims.

My invention relates in general to telescopes and has more particularreference to telescopes adapted for use in surveying instruments such aslevels, transits, and the like, the present application comprisingsubject-matter divided from my copending application, Serial No.188,595, filed February 4, 1938.

An important object is to provide telescopes of improved streamlinedappearance and of simplified construction whereby. operation of theinstrument is facilitated, the operating parts being designed to excludedirt, moisture and other foreign matter from entering the same andcausing deterioration.

Another important object is to provide a telescope having an adjustablepart therein and adjusting means accessible from outside of thetelescope and operable to adjust the part within the telescope,including closure means for preventing entry of foreign matter into thecasing r of the telescope at said adjusting means.

Another important object is to provide an instrument comprising atelescope having focusing means shiftable within the barrel of thetelessope and adjusting means accessible from outside of the barrel ofthe telescope for shifting the focusing means *within the barrel anddust-proof means aifor ding conneotion through the telescope barrelbetween said focusing and adjusting means.

Another important object is to provide dustexcluding adjusting means forthe objective focusing slide of a telescope comprising a handle exposedoutwardl of the telescope and operable to adjust the objective slidewithin the instrument.

Numerous other objects and advantages of the invention will be apparentfrom the following description, which, taken in connection with theaccompanying drawing, discloses preferred embodiments of the invention.

Referring to the drawing,

Figure 1 is a perspective view of a telescope embodying my presentinvention;

Figure 2 is an enlarged sectional view taken substantially along theline 22 in Figure 1; and

Figure 3 is a similarly enlarged sectional view illustrating a modifiedconstruction.

To illustrate my invention, I have shown, on

the drawing. a telescope l5 of substantially streamlined appearance. Thetelescope in the illustrated embodiment comprises a tubular barrel ll ofpreferably cylindrical configuration, which may be belied or enlarged atone end as at It to receive an objective lens assembly 2|. The end ofthe telescope opposite from the objective lens assembly may be providedwith an eye-piece assembly 23, the exposed portions of which arepreferably shaped to a bullet nose configuration in order to improve theappearance of the telescope and reduce wind resistance.

A laterally projecting manually operable knob 25 is also provided uponthe barrel of the telescope to enable adjustment of a focusing slide ofany suitable or convenient form within the barrel of the telescope.Opposite the inner end of the eyepiece assembly 23 a cross-hair reticlemay be arranged. This reticle may comprise a part adjustable within thebarrel of the telescope as by means of threaded adjusting screws mountedradially on the reticle and extending through a circumferentiallyarranged series of openings in the wall of the barrel opposite theposition occupied by the reticle therein.

The reticle adjusting screws have heads received in a closure assembly3| carried on the barrel and comprising a frame 33 formed with anannular channel, in which the heads of the adjusting screws arereceived. A removable cover 31, adapted for mounting on the frame inposition to sealingly enclose the heads of the adjusting screws in theannular channel may be provided.

.The barrel ll of the telescope carries focusing means comprising ashiftable element Ill carrying a focusing lens within the barrel betweenthe eyepiece and vthe objective cell 2|. The shiftable elementpreferably comprises a sleeve Ill mounted for longitudinal movementwithin the barrel, and focusing is accomplished by moving this sleeve inorder to vary the spacement between the objective cell and the focusinglens carried by the sleeve. I provide suitable dust-proof means forshifting the focusing sleeve within the barrel of thetelescope inresponse to manipulation of the knob 25 outside of thebarrel. Thefocusing sleeveis provided with a slot, and a rack H3 is fastened to theinner wall of the sleeve adjacent the slot. The barrel of the telescopealso is formed with a preferably circular perforation H5 opposite theelongated slot of the focusing sleeve and carries an upstandingprojection H1 comprising a sleeve, collar or boss on the outer walls ofthe telescope, said projection having a channel in alignment with theperforation H5. The projection receives and supports a sleeve or bushingH9 in the channel thereof, said bushing forming a tapered bearing for acorrespondingly tapered shaft IZI, one end of which extends within thebarrel of the telescope and carries a pinion I23 is position in theelongated slot of the focusing sleeve to engage said rack H3. Thebushing H9 snugly fits within the channel of the collar II! and is heldin place in any suitable fashion as by the set screw I25. The shaft I2Ihas an end l2! extending upwardly of the bushing II9, said shaftextension being of reduced diameter and carrying the knob 25. Meansforming a dependent skirt on the knob is provided and, as shown inFigure 2, may comprise a sheet metal element I29 which overlies theoutwardly .facingends of the collar Ill, bushing H9, and the shoulderI3I formed at the junction of the tapered shaft portion |2I and theshaft extension I21. The peripheral portions of the sheet metal elementI29 preferably form an annular flange overlying the outer surfaces ofthe collar Ill. The purpose of the element I 29 is to prevent access offoreign matter into the barrel of the telescope through the outer endsof the elements II! and I I9. The outer extremity of the shaft extensionI 21 carries the focusing knob 25, which is held snugly in place thereonby means of a nut I35 threading on said shaft extension and seating in asocket I31 formed in the upper surface of the knob. The knob and nut areof preferably streamlined configuration and the knob may be knurled atits peripheral edges as shown at I39 K to facilitate turning of thesame. The knob also may be provided with an annular roove MI on itsunder side in order to reduce its weight.

In Figure 3, I have shown a modified form of the dust-proof focusingmechanism, in which the shield I29 is eliminated and the knob 25 isprovided with a dependent skirt M3 extending in position to embrace theupper portions of the collar II'I so that the knob itself encloses andprevents entrance of foreign matter through the outer ends of theelements II! and I I9. The skirt portions I43 of the knob and the lowerportions of the collar II'I may have their outer surfaces lying in acontinuous streamlined plane in order to improve the external appearanceof the dust-proof focusing mechanism.

The eyepiece assembly 23 comprises a lenscarrying tube or frame I45enclosed in the end of the telescope barrel. The tubular lens elementI45 projects from the barrel at its outer end through a turnableadjusting collar I59 and is provided with a cover affording a peep holeopposite the outer end of the lens tube I45. The cover I'II has outerlateral surfacesformed to continue the configuration of the outersurfaces of the part I59, and the cover may be formed with an annularflange slidably fitting into a groove in the collar I59 to provide forrelative longitudinal movement between the parts. while preventing theentrance of foreign U0 matter into the assembly.

If desired, the peripheral surface of the rotatable member I59 and theadjacent end of the telescope barrel, may be formed with an index l9!and cooperating scale I93 adapted to indicate the adjustment of theeyepiece, the scale 5% being preferably on the rotatable head I59.

It will be seen from the foregoing that the unit is dust-proof and thatits exposed portions afford an attractive streamlined appearance in 70the telescope. The reticle closure assembly affords means preventingforeign matter from entering the telescope barrel while at, the, sametime furnishing an attractive streamline appearance on the telescope. 7

justable support for an optical element barrel, said barrel having alateral opening, a sleeve secured on said barrel at said opening andhaving an end communicating therewith, a bushmg secured in said sleevewith an end of the bushing extending into said barrel opening, the otherend of said bushing extending outwardly of said sleeve, adjusting meanscooperatively associated with the adjustable support within the barreland having a portion extending in said bushing, said adjusting meanshaving a portion exposed outwardly of said bushing and sleeve andadapted for manipulation from outside of the barrel to move theadjustable support within the barrel, and means forming an annular skirton the outwardly exposed portions of said adjusting means in positionsnugly embracing and movable upon the surfaces of said bushing outwardlyof said sleeve to form a running seal therewith whereby to preventforeign matter from entering the barrel through said sleeve and bushing.

Finally, the assembly provides for substantially dust-proof operation ofthe internal mechanism from the exterior of the barrel, the exteriorportions of the focusing assembly being of attractive streamlinedappearance.

It is though that the invention and numerous of its attendantadvantageswill be understood from the foregoing description, and it is obviousthat numerous changes may be made in the form, construction, andarrangement of the several parts of the illustrated apparatus withoutdeparting from the spirit or scope of my invention or sacrificing any ofits attendant advantages, the preferred modes and forms herein describedbeing merely for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. A telescope comprising a barrel, an adjustable support for an opticalelement in the barrel, said barrel having a lateral opening, asleeveseciued on said barrel at said opening and communicatingtherewith, a bushing secured in said sleeve and opening at one end uponsaid barrel and at the other end outwardly of said sleeve, adjustingmeans journaled in said bushing and cooperatively associated with saidadjustable support within the barrel, said means having a portionextending in said opening and a portion exposed outwardly of saidbushing, and adapted for manipulation from outside of the barrel to movethe adjustable support within the barrel, and means forming an annulardependent skirt on the outwardly exposed portions of said adjustingmeans in position to snugly embrace and ride upon the outer cylindricalsurfaces of said bushing whereby to prevent the entrance of foreignmatter into the barrel between the adjusting means and said bushing.

2. A telescope comprising a barrel, an adin the 3. A telescope as setforth in claim 1, wherein the sleeve forms an annular seat encirclingsaid bushing in position to engage the terminal edge of said annularskirt to form a running seal between said sleeve and said skirt.

4. A telescope as set forth-in claim 1, wherein cured on the outwardlyexposed portions of said adjusting means in position to clamp the bottomof said shell between said knob and said outwardly facing shoulder.

5. A telescope comprising a barrel, an adjustable support for an opticalelement in the barrel, said barrel having a lateral opening, a sleevesecured on said barrel at said opening and communicating therewith, abushing, secured in said sleeve, and opening at one end upon saidbarrel, and opening at the other end outward- 1y of said sleeve,adjusting means comprising a stem having a tapered portion journaled insaid bushing and tapering toward the outer end of the bushing, said stembeing drivingly connected with said adjustable support within the barreland having an end extending outwardly of said bushing, said stem beingformed with an outwardly facing shoulder at the outer end of saidbushing, and means clampingly secured on the outwardly extendingportions of said stem against said shoulder and comprising a manuallyoperable knob adapted for manipulation outwardly of the barrel to turnsaid stem and thus move the adjustable support within the barrel and anannular dependent skirt snugly embracing and riding upon the outercylindrical surfaces of the bushing to thereby prevent entrance offoreign matter into the barrel through said sleeve and bushing.

ADOLPH LANGSNER.

